Start work on zsh completion serialization

tools/completion/zsh.go

@@ -0,0 +1,48 @@
+// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>
+
+package completion
+
+import (
+	"bufio"
+	"fmt"
+	"strings"
+)
+
+var _ = fmt.Print
+
+func zsh_input_parser(data []byte, shell_state map[string]string) ([][]string, error) {
+	matcher := shell_state["_matcher"]
+	q := strings.Split(strings.ToLower(matcher), ":")[0][:1]
+	if strings.Contains("lrbe", q) {
+		// this is zsh anchor based matching
+		// https://zsh.sourceforge.io/Doc/Release/Completion-Widgets.html#Completion-Matching-Control
+		// can be specified with matcher-list and some systems do it by default,
+		// for example, Debian, which adds the following to zshrc
+		// zstyle ':completion:*' matcher-list '' 'm:{a-z}={A-Z}' 'm:{a-zA-Z}={A-Za-z}' 'r:|[._-]=* r:|=* l:|=*'
+		// For some reason that I dont have the
+		// time/interest to figure out, returning completion candidates for
+		// these matcher types break completion, so just abort in this case.
+		return nil, fmt.Errorf("ZSH anchor based matching active, cannot complete")
+	}
+	raw := string(data)
+	new_word := strings.HasSuffix(raw, "\n\n")
+	raw = strings.TrimRight(raw, "\n \t")
+	scanner := bufio.NewScanner(strings.NewReader(raw))
+	words := make([]string, 0, 32)
+	for scanner.Scan() {
+		words = append(words, scanner.Text())
+	}
+	if new_word {
+		words = append(words, "")
+	}
+	return [][]string{words}, nil
+}
+
+func zsh_output_serializer(completions []*Completions, shell_state map[string]string) ([]byte, error) {
+	return nil, nil
+}
+
+func init() {
+	input_parsers["zsh"] = zsh_input_parser
+	output_serializers["zsh"] = zsh_output_serializer
+}